The long-term goal of this research is to test the hypothesis that the generationof acid in the body resulting from the consumption of exessive amounts of dietary protein leads to the loss of calcium-containing buffers from the skeleton which, over several years, contributes to decreased bone mass, osteoporosis, or other forms of bone disease. We hope to explore, through the following experiments, the relationship between dietary protein, acid formation in the body, urinary calcium and boen loss in an ethnically-diverse population of paremenopausal women. We also plan to investigate whether or not orally-administrated buffers can reverse the calcium-wasting effect of excess protein in the same subject population. Taken together, these experiments and studies could constitute a significant first step in our efforts to understand one of the possible mechanisms underlying the development of osteoporosis.